Diseases of the periodontium and teeth caused by microorganisms are prevalent worldwide and these microorganisms are the primary cause of disease of the periodontium and tooth decay and loss in adults.
After teeth are cleaned, they soon become coated with "plaque" which is comprised of organic deposits from saliva, desquamated epithelial cells and masses or oral microorganisms which not only cause cavities in the teeth, but are also believed to be the cause of chronic disease of the periodontal tissues.
The customary techniques heretofore employed for removing plaque and the bacteria contained therein surrounding the teeth is mechanical scaling or root planing of the teeth by a dentist or oral hygienist or flossing and brushing of the teeth by the patient.
The specific identity of the microorganisms which cause periodontal diseases may vary. Pathogens which have been implicated as causing periodontal disease include Actinomyces viscosus (ATCC 19246), Bacteroides intermedius (ATCC 33563), Bacteroides gingivalis (ATCC 33277), Fusobacterium nucleatum, Staphylococcus aureus (ATCC 6538), Candida albicans (ATCC 10231) and E. Coli virus. Although certain materials such as alcohol, iodine and the like have been used in the preparation of oral lavages or antiseptics to control periodontal disease, none of these has been found to be sufficiently effective in controlling the causative microorganisms and hence the disease.
Recent research has shown that periodontal disease can be controlled and treated by the use of certain topically applied antimicrobial agents. Chlorhexidine has, for example, been proved effective in treating periodontal disease. However, the Federal Drug Administration has not permitted this topical agent to be marketed in the United States because of toxicity or cosmetic problems, even though the agent has been shown to be effective in the treatment of periodontal disease. There is thus still a need for an effective oral lavage to treat and control periodontal disease and which is cosmetically acceptable and free of toxicity problems.
Recently, Dr. Paul H. Keyes and Associates proposed a method for controlling periodontal disease by daily brushing of the teeth and gums with a dentifrice comprised of a thick mixture of baking soda moistened with a 3% solution of hydrogen peroxide. Following brushing of the teeth and massaging of the gums with this paste, the mouth is rinsed with salt water. Although this technique has received considerable publicity and has been used by many individuals, its claimed benefits have not been substantiated or reproduced by controlled experimentation. In addition, the high sodium concentration of ingredients used in this technique may be undesirable for use by individuals suffering from hypertension.
Although, in theory, a wide variety of antimicrobial agents and "oxygenating" agents may be and have been considered as components for the antimicrobial compositions embodied in this invention, practical selections are limited by the chemical compatibility of prospective pairs, the physico-chemical properties of the components and their mixtures, including solubility, pH and viscosity, and by safety in use which is dependent on various toxicological characteristics. Some pairs are mutually incompatible, thus yielding mixtures whose effectiveness in ameliorating periodontal disease are in fact effectively less than that of the components.
In our application Ser. No. 565,661 filed Dec. 30, 1983, now U.S. Pat. No. 4,521,403, issued June 4, 1985, we have described an oral lavage and its preparation, which oral lavage comprises povidone iodine complex (PVP-I) and hydrogen peroxide (H.sub.2 O.sub.2), and its application to the periodontium and teeth wherein the oral lavage has enhanced antimicrobial and anti-plaque activity, particularly when the PVP-I and the H.sub.2 O.sub.2 are in certain proportional relationships and concentrations. The use of the PVP-I and H.sub.2 O.sub.2 in combination as an aqueous or aqueous alcoholic solution for the indicated purposes has in particular been found to be very highly effective against the bacteria Actinomyces viscosus (ATCC #19246), Bacteroides intermedius (ATCC #33563) and Bacteroides gingivalis (ATCC #33277). The PVP-I and the H.sub.2 O.sub.2 are most effective when they are formulated as a freshly prepared aqueous or aqueous alcoholic solution; and when kept physically out of contact with one another in a suitable segmented or compartmented package or container, they have a very satisfactory shelf life up to at least about 6 months. The contents of said application are hereby fully incorporated herein by reference.
PVP-I is well known as a complex or adduct of polyvinylpyrrolidine and iodine and is readily soluble in water. The PVP-I is known as a topical disinfectant which is considered to be due to the release of iodine in aqueous or aqueous alcoholic solution. However, the PVP-I complex by itself is characterized by an insufficient antimicrobial action to ensure destruction or inhibition of the major aerobic and anaerobic pathogens generally present in the oral cavity of humans and recognition of this leads to the requirement for the presence of a peroxy compound or oxidizing agent which releases oxygen to enhance the antimicrobial activity of the PVP-I and to provide protection against the build up of plaque on the teeth.
While there are other ways of destroying the pathogens or inhibiting plaque formation on the teeth, such usually involve cleaning or abrasive and/or anti-infective materials and if not properly formulated are capable of damaging the dentine or enamel of the teeth and have insufficient antimicrobial and anti-plaque action to obtain the benefits of the present invention and hence form no part thereof.
It is also known that H.sub.2 O.sub.2 is a mild topical anti-infective agent but aqueous solutions of high concentration of H.sub.2 O.sub.2 would be detrimental if applied to the periodontium and to human tissue and teeth so that it is necessary to use a weak or mild solution of H.sub.2 O.sub.2, preferably not exceeding 3% and/or to use the H.sub.2 O.sub.2 in predetermined proportion with relation to the PVP-I.